Ursa Major Technologies

[PhotoEngineer]

It looks like Ursa stripped the Samus engine off their website

Samus: est 10/2019; ret 04/2020. RIP.

Darn, Samus is a cool name for an engine.

[jongoff]

It looks like Ursa stripped the Samus engine off their website

Samus: est 10/2019; ret 04/2020. RIP.

Darn, Samus is a cool name for an engine.

Thought it's not clear if that means they're not doing it anymore, or they just decided not to talk about it since it's so early stage. Last time I visited, it was still a thing.

~Jon

[jongoff]

It looks like Ursa stripped the Samus engine off their website

Samus: est 10/2019; ret 04/2020. RIP.

Darn, Samus is a cool name for an engine.

Thought it's not clear if that means they're not doing it anymore, or they just decided not to talk about it since it's so early stage. Last time I visited, it was still a thing.

~Jon

Yup, still a thing: https://twitter.com/Ursa_Major_Tech/status/1256018346136371200

[ParabolicSnark]

Cool - thanks for settling that one Jon.

I look forward to the update specs, images, and hopefully more information about who it could be for (wishful thinking).

[jongoff]

https://twitter.com/ursamajortech/status/1301657943935528964
https://www.instagram.com/p/CEsTXJ8hl9X/?igshid=6kxweehs3nzq

Cool picture of a firing of their Ripley 35klbf first stage engine on their new test stand.

Also it looks like their website got a makeover (https://www.ursamajortechnologies.com/), and Samus is back on the engines page...

~Jon

[Steven Pietrobon]

Images of the test.

[TrevorMonty]

https://twitter.com/ursamajortech/status/1301657943935528964
https://www.instagram.com/p/CEsTXJ8hl9X/?igshid=6kxweehs3nzq

Cool picture of a firing of their Ripley 35klbf first stage engine on their new test stand.

Also it looks like their website got a makeover (https://www.ursamajortechnologies.com/), and Samus is back on the engines page...

~Jon

Who are their customers? Most of up and coming small LVs are using inhouse engines. ULA maybe customer for Samus but given how reliable RL10 has been it's risking move.

[GWF]

Jon, that is a Hadley engine on the new stand.

[jongoff]

Jon, that is a Hadley engine on the new stand.

Is it? I just assumed it was a Ripley, since that's what was on that stand when I got a tour earlier in the year.

~Jon

[GWF]

Jon, that is a Hadley engine on the new stand.

Is it? I just assumed it was a Ripley, since that's what was on that stand when I got a tour earlier in the year.

~Jon

The Instragram post was updated confirming its Hadley.  You can also zoom in on the picture and see the engine is mounted on an adapter.


Gary

[jongoff]

Jon, that is a Hadley engine on the new stand.

Is it? I just assumed it was a Ripley, since that's what was on that stand when I got a tour earlier in the year.

~Jon

The Instragram post was updated confirming its Hadley.  You can also zoom in on the picture and see the engine is mounted on an adapter.

Ah, that update came out after I had originally linked to it. I wonder why they have a Hadley on Stand B.

~Jon

[Robotbeat]

Samus sounds SUPER interesting... hydrolox staged combustion UPPER stage engine... 50,000lbf thrust! That thing should, with a big bell extension and an appropriate fuel mixture, get higher Isp than RL-10, twice the thrust with perhaps the same mass (and probably a LOT cheaper). It'd be a very nice upgrade to a vehicle like Vulcan.

[PhotoEngineer]

Samus is back on the engines page...

~Jon

Sweet!  With Ursa and Relativity I'm loving the video game references, our generation has arrived

These are really nice looking engines, clean designs.  Would be curious if they struggled with some of the ductwork prints at all. Must be some interesting geometry, stresses, etc.

[ParabolicSnark]

Samus sounds SUPER interesting... hydrolox staged combustion UPPER stage engine... 50,000lbf thrust! That thing should, with a big bell extension and an appropriate fuel mixture, get higher Isp than RL-10, twice the thrust with perhaps the same mass (and probably a LOT cheaper). It'd be a very nice upgrade to a vehicle like Vulcan.

But who would buy it? The companies that buy engines like RL-10 aren't trying to save money, they're chasing the tenth's of a percent of reliability. It is inconceivable that Ursa could do enough testing on Samus and every part that touches Samus to give it the same reliability of the venerable RL-10.

[JEF_300]

It's been a while since I've looked at Ursa Major, and it looks like they've been doing good work.

Samus is obviously an incredibly interesting engine. If any one of the many organizations operating RL-10s can summon the courage to take a chance on it, then it's an almost guaranteed success. Otherwise, it's doomed to failure.

Ripley is most obviously interesting as a first stage engine for small-sat launchers (From Electron-class with 1 Ripley to 1-ton-class with 4-5 Ripleys). But all the small-sat launcher companies I know of with a prayer of succeeding are building their own engines. I think perhaps it could find a place as the upper stage engine of Firefly's Beta rocket, assuming they're still planning to use the AR1 for the first stage. It's about the right sized for an 8-ton to LEO launcher's upperstage.

[Robotbeat]

Samus sounds SUPER interesting... hydrolox staged combustion UPPER stage engine... 50,000lbf thrust! That thing should, with a big bell extension and an appropriate fuel mixture, get higher Isp than RL-10, twice the thrust with perhaps the same mass (and probably a LOT cheaper). It'd be a very nice upgrade to a vehicle like Vulcan.

But who would buy it? The companies that buy engines like RL-10 aren't trying to save money, they're chasing the tenth's of a percent of reliability. It is inconceivable that Ursa could do enough testing on Samus and every part that touches Samus to give it the same reliability of the venerable RL-10.

The RL-10 is so expensive that it makes whichever launcher needs it, especially if it needs two or more of them, noncompetitive for commercial launch.

Samus could be so high performance that it might make a good choice for air-launched SSTO (think like that SSME variant that Boeing was going to use for their Darpa vehicle but then pulled out because they're Boeing).

[jongoff]

Samus sounds SUPER interesting... hydrolox staged combustion UPPER stage engine... 50,000lbf thrust! That thing should, with a big bell extension and an appropriate fuel mixture, get higher Isp than RL-10, twice the thrust with perhaps the same mass (and probably a LOT cheaper). It'd be a very nice upgrade to a vehicle like Vulcan.

That was my thinking too. That and it would be a great engine to then add LOX-Rich TAN to to turn it into an SSTO engine... But I should probably can the fan-fic, and see if they can get the funding and then make their actual plans for Samus work. Their baseline goals should already be cool enough to get any self respecting rocket nerd salivating Pavlovianly... :-)

~Jon

[novak]

Samus sounds SUPER interesting... hydrolox staged combustion UPPER stage engine... 50,000lbf thrust! That thing should, with a big bell extension and an appropriate fuel mixture, get higher Isp than RL-10, twice the thrust with perhaps the same mass (and probably a LOT cheaper). It'd be a very nice upgrade to a vehicle like Vulcan.

Seems to me generally unlikely that a high pressure staged combustion engine would be double the thrust but lighter (eg, twice the pressure is twice the weight), and Isp is a very weak function of chamber pressure- 500psi to 2000 psi is a little over one second of Isp theoretical.  Note specifically that this is different that booster engines where high PC means high vacuum Isp because you can now run a larger nozzle at sea level.  Though, with a brazed tube nozzle, some weight savings may be pretty attainable.  But expander cycle is already pretty high performance.

However, agree that the RL10 is ancient, "craftsmen" type engineering that should be somewhat low hanging fruit to improve upon, especially on cost.  Interested to see the development costs as well, as hydrolox engines have historically been very expensive, so it will be interesting to see what newspace can do here.

That was my thinking too. That and it would be a great engine to then add LOX-Rich TAN to to turn it into an SSTO engine... But I should probably can the fan-fic, and see if they can get the funding and then make their actual plans for Samus work. Their baseline goals should already be cool enough to get any self respecting rocket nerd salivating Pavlovianly... :-)

~Jon

Engines intended for operation at both sea level and high altitude generally have very complex and different rocket nozzles- eg, the SSME, which did not use a thrust optimized contour but rather one to get the maximum vacuum thrust without sea level separation.  It doesn't seem optimal for an engine without that being the direct goal.  As you say, the engine ought to be able to stand apart from any SSTO dreams.

[jongoff]

Engines intended for operation at both sea level and high altitude generally have very complex and different rocket nozzles- eg, the SSME, which did not use a thrust optimized contour but rather one to get the maximum vacuum thrust without sea level separation.  It doesn't seem optimal for an engine without that being the direct goal.  As you say, the engine ought to be able to stand apart from any SSTO dreams.

The idea of TAN (Thrust Augmented Nozzles, as patented by Aerojet) is to inject extra propellant into the nozzle, slightly downstream of the throat, in a way that lets it combust and expand partially in the nozzle. This gives you much higher thrust (at lower Isp) for the atmospheric portion, while also preventing flow separation. You eventually shut the TAN injection off at a certain point and switch to normal high-altitude/vacuum operations. But yeah, this isn't something Ursa is planning, so further discussion probably doesn't belong here.

~Jon

[TrevorMonty]

However, agree that the RL10 is ancient, "craftsmen" type engineering that should be somewhat low hanging fruit to improve upon, especially on cost.  Interested to see the development costs as well, as hydrolox engines have historically been very expensive, so it will be interesting to see what newspace can do here.

ARJ have spent lot effort modernizing RL10 for additive manufacturing technology. Given its excellent flight history they have good reason to take slow cautious approach to changing RL10 design. Whether they've passed build cost savings onto customers is unknown, but I'd be surprised if they havn't.